2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/105796This is a study of the behavior of wave equations in conformally compactified spacetimes suited to the use of computational boundaries beyond Scri+. There light cones may be adjusted for computational convenience and/or Scri+ may be approximated by a "proto-Scri" spacelike hypersurface just outside a de Sitter horizon. One expects a numerical implementation to excise the physically unnecessary universe somewhat beyond the outer horizon. As an entry level example I study forms of the Maxwell equations and causal relations for an outer boundary in that example.5 pages, no figures; added acknowledgements and references in v2General Relativity and Quantum Cosmologytext